Snap acting device



E. F. KOHL SNAP ACTING DEVICE Jan. 11,1949.

4 Shets-Sheet 1 Filed May 15, 1944 E'. F. KoHL SNAP ACTING DEVICE Jan.ll, 1949.

4 Sheets-Shes?I 2 Filed May 15, 1944 INVENTOR. BY Ere/aro//F/fa// 477V 7Jan. l1, 1949. E. F. KoHl. 2,458,518

SNAP ACTING DEVICE Filed May 15, 1944 4 Sheets-Shawl'l 5 INVENT OR.

Jan. 11, 1949. 4 E.- F. KoHl. 2,458,518

SNAP ACTING DEVICE Filed May 15, 1944 4 sheets-sheet 4 'IN1/ENT Eve/ardF/fo Patented Jan. 11, 1949 UNITED STATES PATENT OFFICE SNAP ACTINGDEVICE Everard F. Kohl, Lakewood, Ohio Application May 15, 1944, SerialNo. 535,709

My invention relates to snap acting devices and more particularly to a.device of this type in which a force is applied to store energy in amember to be actuated to provide snap motion when the applied forceexceeds a predetermined amount.

In electrical switches of the snap acting type, it has heretofore beenthe practice to apply an actuating force to a lever through a spring ortoggle arrangement to move a contact carrying arm in the oppositedirection. Snap acting switches have also been constructed in whichpressure has been applied to a flexible contact carrying member againstan`V opposing force to provide snap motion of the member when thepressure of the opposing force is exceeded. Such switches are not verysensitive, however, because the opposing force is usually provided bymeans of a spring that must be compressed to a considerable extentduringmovement of the member to be actuated. It is the purpose of thepresent invention to provide a snap acting device of this type in whichthe direction of the opposing force of the spring is quickly changedwhen sufficient energy has been stored in the member to be actuated toovercome the opposing force of the spring and consequently rapid motion.of the member to be actuated takes place. This change of direction ofthe force of the spring also takes place when the actuated memberreturns, or is returned to its original position, and consequently myimproved device is particularly suitable for use in electrical switchesrbecause it provides a quick `make and break of contacts carried by themember'to be actuated and fixed contacts arranged on opposite sides ofthe contact carrying member, thus minimizing volatilization at thecontacts. My invention also contemplates providing means to adjust theforce opposing movement of the member to be actuated to provide a snapacting device that may be actuated by any desired pressure of theactuator.

It is therefore one of the objects of the present invention to providean improved snap acting device in which energy is. stored in a member tobe actuated against an. opposing force during the initial movement of anactuator to cause a snap motion of said member when the force of theactuator exceeds the opposing force.

Another object of the invention is to provide 15 Claims. (Cl. ZOO-67) animproved snap acting device in which energy Y when the force of theactuator exceeds the opposing force, including means for adjusting theopposing force to regulate the amount of pressure required to actuatethe device.

A further object of my invention is to provide an improved snap actingswitch in which energy is stored in a contact carrying member during theinitial movement of an actuator against an opposing farce and in whichthe direction of the opposing force changes quickly when the contact onthe carrying member is moved from engagement with a iixed contact.

Another object of the invention is to provide an improved snap actingdevice in which the parts may be easily and simply constructed andreadily assembled in place.

A still further object of my invention is to provide a simple andimproved means for permitting over travel of an actuator when the partsreach their actuated position.

Other objects and advantages of my invention will be -apparent as thespecification proceeds when taken in conjunction with the accompanyingdrawings although it will be understood that the drawings are merelyillustrative as my improved device may be utilized in conjunction withFig. 4| is a View similar to Fig. 3 with the parts` in the actuatedposition;

Fig. 5 is a plan view of a stamping from which the contact carrier andspring support is formed;

Fig. 6 is a perspective view of the stamping after it has been formedfor assembly;

Fig. 7 is a view showing the loose connection 3 between the spring andprojections on the contact carrier and spring support;

Fig. 8 is a side elevational view of the upper portion of the switchwith the cover in section and showing in elevation means to permit overtravel of the actuator.

Fig. 9 is a plan view of the spring which permits over travel of theactuator;

Fig. 10 is a view similar to Fig. 8 with the parts in actuated position;

Fig. 11 is a cross sectional view on the line II-II of Fig. 10, lookingin the direction of the arrows;

Fig. 12 is a view of the upper portion of the switch, showing thearrangement of the parts when the switch is to be actuated through deadcenter;

Fig. 13 is a view similar to Fig. 12 with the parts in a differentposition;

Fig. 14 is a plan view of a modified form of switch with parts brokenaway to show underlying structure;

Fig. 15 is a side elevational view of the switch shown in Fig. 14 withthe cover and other parts of the switch in section;

Fig. 16 is a fragmentary portion of the switch shown in Fig. 15 with theparts in the actuated position;

Fig. 17 is a side elevational view of a modified form of my improvedswitch attached to a base, a fragmentary portion of which is shown inelevation;

Fig. 18 is a view similar to Fig. 17, showing an other modification ofmy improved switch;

Fig. 19 is a view similar to Fig. 18 with the parts in a differentposition; and

Figs. 20 and 21 are cross sectional views on the lines 20--20 and 2I-2I,respectively, of Fig. 19. While my improved snap acting device may beconstructed in various ways and utilized for any suitable purpose, inFigs. l to 7 of the drawings it is illustrated as forming part of anelectrical switch in which the free end of flexible contact carrier I ismovable between a pair of spaced contacts 2 and 3 against the force of aspring 4, one end of which engages the contact carrier adjacent its freeend and the other end of which engages a downwardly biased arm orsupport 5.

The means for supporting my improved device will of course depend uponthe function it is desired to perform and the particular apparatus withwhich it is associated. For purposes of illustration, an assembly isshown comprising a base 6 formed of a suitable insulating material, suchas a molded phenolic condensation product, having a downwardly inclinedportion 'I and a cover 'Ia which is also preferably formed of a similarmolded material. The cover is provided with an aperture which receives afreely slidable plunger 8 for moving the contact carrier against theforce of spring 4, the head or button 9' of which plunger is alsopreferably formed of molded insulating material.

While the contact carrier I and the arm or support 5 may be formedseparately, they are preferably stamped from a sheet of thin springstock as illustrated in Fig. 5 with a lug or tongue I0 extending fromarm 5, a U-shaped slot II formed at the junction of arm 5 and contactcarrier I, and a slot I2 formed in the contact carrier into whichextends a lug or tongue I3. The contact carrier I, and arm 5 aretherefore resilient. Aperture I4 is also preferably punched in thematerial for purposes to be described.

The stamping is bent on substantially the line Means associated with thebase are providedv for suitably securing the preformed stamping in placeand for establishing an electrical circuit when a contact arranged onone side of the contact carrier engages contact 2 and a differentelectrical circuit when the contact on the opposite side of the carrierengages contact 3. To provide Contact between the stamping and oneterminal of an electrical circuit, the preformed stamping is arrangedupon the base with one end in contact with an internally threaded insertI5 and the aperture I4 in the stamping aligned with the bore of theinsert to receive the shank of a headed screw I6 which as shown isinserted through a washer, the apertur-e in the stamping, and isthreaded in insert I5. Insert I5 is embedded in the base 6 and itsopposite end receives terminal screw I'I. Contacts 2 and 3 may be of anydesirable shape and are connected to suitable terminals in anyconvenient manner. As illustrated, contact 2 is of angular shape withone leg resting upon a projection I8 through which an internallythreaded metal insert I9 extends which receives a terminal screw 20 andin a like manner an internally threaded metal insert 2| extends throughleg 22 of contact 3 to receive a suitable terminal screw not shown.

As illustrated in the drawings, the free end of contact carrier I isprovided with contacts 23 and 23a, contact 23 being in engagement withthe contact 2 when the switch is in the position shown in Fig. 2 andcontact 23a being in engagement with contact 3 when the parts are in theposition shown in Fig. 4.

Contact 23 is normally held in engagement with contact 2 by means of aspring 4, one end of which engages the downwardly biased arm or support5 and the other end of which engages contact carrier I. The spring 4 maybe of any suitable form which is capable of maintaining contact 23 inengagement with contact 2 and which is capable of rocking upon thetongues or projections formed upon contact carrier I and arm 5, or uponthe abutments or shoulders adjacent the tongues, to quickly change thedirection of its force when a sufficient amount of pressure is appliedto the contact carrier I adjacent its fixed end. Preferably, the springis of arcuate shape, as shown in Patent No. 2,237,705 granted to me onApril 8, 1941, and which is here illustrated in detail in Fig. 7, andwhile it may be preformed, it preferably consists of a thin fiat pieceof resilient metal of spring temper, such as steel, a beryllium-copperalloy, bronze, or similar material, and is provided with slots orapertures in the margins adjacent each end, one of which looselyreceives tongue or lug I0 and permits the portion of the spring adjacentthe aperture to bear against shoulders or abutments 25 and 26 and theother end of which loosely receives tongue or lug I3 and bears againstthe shoulders or abutments 21 and 28 adjacent tongue I3 when the springis compressed into an arcuate shape.

The apertures or slots are wider than the respective tongues I0 and I3to permit free rocking assasia movement of the spring upon the abutmentsor shoulders adjacent tongues Il and I3. They should not, however, besubstantially wider than is necessary for this purpose. otherwise thespring isliable to become disengaged from the tongues in service.

l-As illustrated in Fig. 2 of the drawings. thek switch parts are innormal position with an electrical circuit established between terminali1, contact carrier I. contact 2, insert I3 and terminal 23. Assumingthat it is desired to interrupt this circuit, or to interrupt thiscircuit and establish a circuit through contact 3 and insert 2| to anadditional terminal, plunger 3 is applied to cono. tact carrier Iadjacent its xed end. Contact 23 f, upon the free end of contact carrierI, however, is

held in engagement with contact 2 by the force of spring 4. During theinitial movement of the plunger 3, contact carrier I yis therefore nrstflexed as shown in dotted lines in Fig. 3 and energy is stored thereinwhich increases as the plunger is moved downwardly but when suillcientenergy is stored in contact carrier I to overcome the upward componentof the force of spring 4, it is forced downwardly with a snap motion.When contact 23 disengages contact 2, the energy stored in conforcerequired to actuate the switch, and while any tact carrier I is 'ofcourse gradually released but this decrease in the stored energy of thecontact carrier is more than offset by the decrease in the upwardcomponent ofthe force of spring 4 which is rapidly rocked upon theshoulders or abutments adjacent tongues I0 and I3, thereby decreasingthe upward component of the force of spring 4.

and consequently contact 23 is movable from en-` gagement with contact 3with a snap motion which is accelerated due to the rapid change indirection of the force of spring). In the construction illustrated, itwill be particularly noted that when contact 23 is moved from contact 2,it causes only a slight additional compression of spring 4 and that thereduction in the upward component of the i'orce of the spring is causedprimarily by the change in direction of the force of the spring.

It will of course be understood that ii it is desired to establish andinterrupt one circuit only. either contact 2 or contact 3 may beutilized as a stop. When only. one circuit is to be interrupted andestablished in the switch shown in Figs. l to 7,it is preferable,however, to interrupt the circuit between contacts 2 and 23 because whencontact 23 `is in the position shown in Fig. 2, it is maintained in firmengagement with contact 2 by the upward component of the force of spring4.

When the parts are in the .position shown in Fig. 4, it will be apparentthat the parts will be returned to the position shown in Fig. 2 with asnap motion when the force upon actuator 3 is released. 'I'his returnmovement takes place be- .cause when the parts are in the position shownin Fig. 4. the upward component of the force of spring 4 while small issufficient to initiate upward movement of the free end of contactcarrier I, and as contact 23a moves from engagement with contact 3,spring 4 is immediately rocked upon the abutments or shoulders adjacenttongues or lugs I0 and I3, thus rapidly increasing the upward componentof the force of spring 4 and returning contact 23 into engagement withcontact 2 with a snap motion where it is held ilrmly in place by theupward component of the force of spring 4 until pressure is againapplied to plunger 8.

In my improved switch, means may also -be provided for adjusting theposition of the downl i6 wardiy biased arm or support l to regulate thesuitable means may be provided for this purpose, as illustrated in thedrawings, a screw 23 threaded in base 3, has an upper pointed end whichbears against the arm or support 3 and its lower end is provided with aslot 3l to receive a suitable tool for adjusting the position o! thescrew. From the drawings, it will be apparent that by adjusting screw 23upwardly.A arm 3 is raised `and the upward component of the force ofspring 4' is reduced. thus enabling' the switch to be actuated with lessforce upon the contact carrier than when the parts are in the positionshown in Fig. 2. On the other hand. when screw 23 is adjusteddownwardly, the free end of arm 3 which is biased downwardly is loweredwhich increases the upward component of the force of spring 4 andconsequently more force is required to actuate the v contact carrierthan when the parts are in the position shown in Fig. 2.

Means may also be provided to permit over travel of the actuator I .whenthe parts have been moved `to their actuated position. Such means aredesirable when the switch is utilized in asso-A ciation with apparatuswhich has the tendency to move the actuating pin too far and place anundue strain upon the contact carrier after the parts have been moved totheir actuated position. For

this purpose, an over travel spring. as illustrated in Figs. 8 to 11 ofthe drawings is inserted between the head 3 of plunger 8 and the contactcarrier I. This spring may be stamped from a single sheet of springmetal and preformed to the shape shown in Figs. 8 and 9. As illustratedin Figs. 8 and 9, the spring comprises a base portion 32 having a boss33 formed thereon which engages contact carrier I and an upper portion34, the iront portion of which is biased upwardly into engagement withYflanges 35 and 36 formed upon spaced tongues 31 and 33 extendingupwardly from the bottom portion. To secure the spring in place,

the bottom portion is provided with a narrow strip the upwardly actingcomponent of the force of spring 4 without changing the position of theupper portion 34 of the spring. When the parts are in the actuatedposition shown in Fig. 10, however, further downward movement of theover travel spring will flex contact carrier I until the resistance ofthe flexed carrier overcomes the force of the over travel spring.Further downward movement of the actuator 3 will then force the upperportion 34 of the over travel spring downwardly without further flexingof the contact carrier as illustrated' in Fig. 10 of the drawing. Theother parts of the switch shown in Figs. 8 to 1l of the drawing aresimilar to the parts shown in Figs. 1 to 7 and have accordingly beendesignated by the same numerals.

The switch shown in Figs. 12 and 13 has the same mode of operation andis similar to that shown in Figs. 1 to 7, inclusive, with the excepttionthat contact 3 is located suillciently below contact 2 so that when thecontact carrier is actuated, its free end is moved below dead centershown in Figs. 14 to 16 of the drawings.

and the downward component of the force of the spring maintains it inthis position and consequently in a switch of this type, a secondactuator 4| is provided having a head 42 which extends through anopening in the arm 5 and engages the contact carrier I to move contact26 in engagement with contact 2 against the downward component of theforce of spring 4 when pressure is applied to the contact carrieradjacentl its fixed end.

Another modication of my improved switrrzllihs S switch is more compactthan the switch shown in Figs. 1 to 7, inclusive, and some of the partsare arranged in a different manner.

As illustrated in the drawings, the base, cover, terminals and theactuator are the same as shown in Figs. 1 to '7 and consequently theseparts have been designated by the same numerals. In the modificationshown in Figs. 14 to 16, however, the contact carrier 43 is formedseparately from the arm or spring support 44 and is provided with aprojection 45 terminating in an eyelet 46 which is held in place by thehead of screw I8 and the free end is provided with contacts 41 and 48,contact 41 being in engagement with a contact 49 on arm when the partsare in the position shown in Fig. 15 and contact 48 being in engagementwith the contact 5I on arm 52 when the parts are in the actuatedposition as shown in Fig. 16. One end of arm or spring support 44 isattached' to the base 6 by any suitable means, such as a rivet 53, andits free end is biased upwardly against the head 54 of a screw 54a whichserves as the means for adjusting the force required to actuate theswitch.

Spring 55, while rockably mounted upon abutments formed on the free endof arm 44 and an abutment formed adjacent the free end of contactcarrier 43, is held in engagement with the carrier and arm in a mannersomewhat diiferent than that shown in Figs. 1 to 7. As illustrated moreparticularly in Fig. 14, notches or slots are formed at opposite sidesadjacent the margins of the free ends of spring 55 and projections ortongues 56 and 56a extending from opposite sides of arm 44-are receivedin the notches or slots at one end of the spring and shoulders orprojections 51 and 58 adjacent the free end of contact carrier 43 arereceived in the notches or slots adjacent the opposite end. It will ofcourse be understood that the notches or slots at one end of the springare wider than the tongues or projections 56 and 56a received thereinand the notches or slots adjacent the other end of the spring are widerthan the shoulders or projections 51 and 58 to permit free rockingmovement of the spring upon the abutment at the end of arm 44 and theabutment adjacent the free end of contact carrier 43. This method ofconnecting the spring 55 to the free end of arm 44 and adjacent the freeend of contact carrier 43 is illustrated in more detail in my copendingapplication, Ser. No. 383,436 filed on March 14, 1941.

The mode of operation of this switch is similar to that shown in Figs. 1to 7 with the exception that when screw 54a is adjusted downwardly theupward component of the force of spring 55 is increased and more forceis required to actuate the switch than when the parts are in theposition shown in Fig. 15. On the other hand when the screw 54 isadjusted upwardly, less force is required to actuate the switch thanwhen the parts are in the position shown in Fig. 15.

Another form of my improved switch is shown in Fig. 17 of the drawingwhich is somewhat similar to that shown in Figs. 1 to '7 with theexception that the arm 5 is not biased downwardly but is free to movewhen the contact 23 is forced from engagement with contact 2. In theoperation of the switch shown in Fig. 17, when actuator 8 is applied tocontact carrier I against the force of spring 4, the contact carrier isfirst flexed as shown in dotted lines in Fig. 17 and when sumcientenergy has been stored in the contact carrier to overcome the force ofspring 4, contact 23 is moved from contact 2 with a snap motion which isaccelerated during movement of contact 23a to contact 3 by the decreasein the upward component of the force of spring 4 which is rocked uponits supports to change the direction of the force of spring 4 which inthe position shown in dotted lines in Fig. 1'7 has a downward componentof force acting upon the free end of contact carrier I and an upwardcomponent of force acting upon the free end of arm 5 which moves thefree end of arm 5 upwardly and maintains it in a stressed condition.When the pressure applied adjacent the fixed end of contact carrier I isreleased, however, arm 5 because of its stressed condition returns toits original position, rocking spring 4 upon its supports to a positionin which it provides an upward component of force upon contact carrierI, thereby returning the parts to their original position with a snapmotion.

The switch illustrated in Figs. 18 to 21 is similar to that shown inFig. 1'7 with the 4:xception that contact 3 is arranged at a suificientdistantc ,3clow contact 2 so that when or-ess" -s applied to actuator 8,the parts wil. emain in their actuated position. It is therefc necessaryto provide an additional actuator to return the parts to their originalposition. For this purpose, an actuator 59 is provided which is freelyslidable through an opening in the cover in the same manner as actuator8 and is provided with a head 60 which rests upon the free end of arm 5.When the parts are in the position shown in Fig. 1, pressure is appliedto actuator 8 to stress contact carrier I and force contact 23 fromengagement with contact 2 with a snap motion when the opposing force ofspring 4 is overcome as more particularly described in connection withthe operation of the switch shown in Fig.17. When it ls desired toreturn the parts' to their original position, pressure is applied toactuator 59 which acts through spring 4 to return the contact carrier toits original position. The advantage of this structure is that actuator8 and 56 may be positioned adjacent to each other and both may slidefreely through apertures in the same cover.

It will be particularly noted that in all forms of my improved device,except in the actuator 59 utilized to return the parts to their originalposition as shown in Fig. 19, the pressure for actuating the device isapplied to the long arm which in case of a switch is the contactcarrier. There is a distinct advantage in applying the force directly tothe contact carrier because in such case positive actuation is obtained.It will also be noted that in applicants improved structure, the contactcarrier is longer than the arm supporting the spring and consequentlyenergy may be more readily stored in the contact carrying member than ina shorter arm acting through the intermediary of a spring or othertoggle arrangement to effect snap motion of the contact carrier.

What I claim is:

1. In combination, a switch having a resilient arm movable from a normalto an actuated position and mechanism for actuating said arm includinga. spring having upper and lower sub-` stantially flat arms with aportion oi the lower arm engaging the resilient arm of said switch andthe upper arm being biased away from the lower arm, means associatedwith the arms of said spring for maintaining them in spaced relation,and an actuator engaging the upper arm of said spring, said spring beingof suicient strength to move the resilient arm of said switch from itsnormal to its actuated position without ilexing said spring whenpressure is applied to said actuator, and the upper arm of said springbeing ilexible to permit overtravel of said actuator after the resilientarm of said switch is moved to its actuated position.

2. In combination, a switch having a resilient member to be actuated, aspring for maintaining said member in a predetermined position,actuating mechanism for said switch including a second spring havingupper and lower substantially at arms with the lower arm being providedwith a boss which rests upon the member to be actuated and the upper armbeing biased away from the lower arm, and means associated with thelower arm of the second spring for maintaining the arms of the secondspring in spaced relation, and an actuator engaging the upper arm of thesecond spring, said second spring being of suiicient strength to movethe resilient member of said switch from its normal to its actuatedposition without flexing the second spring when pressure is applied tosaid actuator, and the upper arm of the second spring being exible topermit overtravel of said actuator after the resilient member of theswitch is moved to its actuated position.

3. In combination, a switch having a resilient member movable from anormal to an actuated position and mechanism for actuating said memberincluding a spring having integral upper and lower substantially at armswith the lower arm being provided with a boss which rests upon theresilient member'and the upper arm being biased away from the lower arm,means integralwith the lower arm for maintaining the arms in spacedrelation, and an actuator engaging the upper arm of said spring, saidspring being of sufficient strength to move the resilient member of saidswitch from its normal to its actuated position -without flexing saidspring when pressure is applied to said actuator, and the upper arm ofsaid spring being iiexible to permit overtravel of said actuator afterthe resilient member of said switch has been moved to its actuatedposition.

4. Apparatus of the class described comprising a stationary contact, aresilient Contact carrier having a xed end and a free end and beingprovided adjacent its free end with an abutment and with a contact whichis arranged opposite to th-e stationary contact and which is movableinto and from engagement therewith, a resilient arm having a free endprojection which is shorter than said contact carrier and whichprojection is provided with an abutment, a spring having its oppositeends rockably mounted on said abutments for normally maintaining themovable contact in engagement with the stationary contact and the freeend projection of said arm in spaced relation to said carrier, and anactuator applied to said carrier adjacent to its fixed end on the sideopposite to that from which the arm is spaced, and said arm beingperpendicularly spaced at a sumcient distance arm to store sumcientenergy in said carrier under the influence of said actuator to move thecarrier with a snap motion when the'opposing force of said spring isexceeded.

5. Apparatus o! the class described comprising a stationary contact, aresilient contact carrier having a fixed end and a free end and beingprovided adjacent its free end with an abutment and with a contact whichis arranged opposite to the fixed contact and which is movable into andfrom engagement therewith. a resilient arm having a free end projectionwhich is shorter than said contact carrier and which projection isprovided with an abutment, a spring rockably mounted on said abutmentsfor normally maintaining the movable contact in engagement with thestationary contact, an actuator applied to said carrier adjacent itsfixed end on the side opposite to that from which the arm is spaced,said arm being perpendicularly spaced at a suilicient distance from saidcontact carrier opposite to the position at which said actuator isapplied to permit suiilcient fiexure of the carrier in the space betweenthe plane of said carrier and the plane of said arm to store suiilcientenergy in said carrier under the iniluence of said actuator to move thecarrier with a snap motion when the opposing force of said spring isexceeded,` and the free end of said arm being biased away from saidcontact carrier and being under suillcient stress to prevent itsmovement during movement of said contact carrier.

-6. Apparatus of the class described comprising rst and second spacedstationary contacts, a resilient contact carrier having a fixed end anda free end and being provided adjacent its free end with an abutment,first and second movable contacts affixed to opposite sides of saidcarrier adjacent its free end, the first being movable into and fromengagement with the rst stationary contact and the second being movableinto and from engagement with the second stationary contact, a resilientarm having a free end projection which is shorter than said contactcarrier and which projection is provided with an abutment, a springhaving its opposite ends rockably mounted on said abutments for normallymaintaining the first movable contact in engagement with the rststationary contact and the free end projection of said arm in spacedrelation to said contact carrier, an actuator applied adjacent the fixedend of said carrier upon the same face thereof which carries the firstmovable contact,vsaid arm being perpendicularly spaced at a sulcientdistance from said contact carrier opposite to the position at whichsaid actuator is applied to permit suflicient ilexure of the carrier inthe space between the plane of said carrier and the plane of said arm tostore sufficient energy in said carrier under the influence of saidactuator to disengage the first movable contact from the firststationary contact against the force of said spring and to rock saidspring uponsaid abutments to rapidly change the direction of the forceof said spring to cause the second movable contact to engage the secondstationary contact with a snap motion, and the abutment on the free endprojection of said arm being spaced sufliciently from the contact`carrier and the xed contacts being so disposed relative to each otherand to the abutl1 ment on said arm that the second movable contactengages the second stationary contact? to limit the movement of thecontact carrier before it passes into alignment with the abutmenton saidarm, whereby said spring retains a component of force which is effectivein initiating the return movement of the first movable contact toengagement with the first stationary contact when the force'upon saidcarrier is released, and the return movement of said carrier beingeffective in causing a rocking movement of said spring upon saidabutments to return the first movable contact into engagement with thefirst stationary contact with a snap motion.

'7. Apparatus of the class described comprising a stationary contact, aresilient contact carrier having a fixed end and a free end and beingprovided with an abutment adjacent its free end, a movable contactfixedadjacent the free end of said carrier, a resilient arm having afree end projection shorter than said contact carrier which projectionis provided with an abutment, a support, means for securing the oppositeend of said arm to said support. the free end of said carrier and thefree end projection on said `arm being extended in the same directionfrom said support and the free end projection of said arm being biasedaway from said carrier, a spring rockably mounted on said abutments andnormally maintaining the movable contact in engagement with thestationary contact, an actuator applied to said contact carrier adjacentits fixed end, and resilient means for perpendicularly spacing said armat a sufficient distance from said contact carrier opposite to theposition at which said actuator is applied to permit suillcient flexureof the carrier in the space between the plane of the carrier and theplane of the arm to store suillcient energy in said carrier under theinfluence of said actuator to disengage the movable contact from thestationary contact with a snap motion.

8. Apparatus of the class described comprising first and second spacedstationary contacts, a resilient contact carrier having a fixed end anda free end, first and second movable contacts affixed to opposite sidesof said contact carrier adjacent its free end and said carrier beingprovided with an abutment adjacent its free end, a resilient arm havinga projection shorter than said carrier which projection is provided withan abutment, a spring rockably mounted on said abutments and normallymaintaining the first movable contact in engagement with the firststationary contact and the free end of said projection in spacedrelation to said carrier, an actuator applied to said carrieradjacentits fixed end on the side opposite to that from which saidprojection is spaced, said arm being perpendicularly spaced at asufficient distance from said contact carrier opposite to the positionat which said actuator is applied to permit suiicient flexure of thecarrier in the space between the plane of said carrier and the plane ofsaid arm to store suflcient energy in said carrier under the influenceof said actuator to disengage the first movable contact from the firststationary contact and force the second movable contact into engagementwith the second stationary contact with a snap motion, thereby rockingsaid spring on said abutments to change the direction of the fonce ofsaid spring to flex said arm in a direction opposite to the movement ofsaid carrier and store energy therein, and the fixed contacts being sodisposed relative to each other and the abutment on said projection thatthe contact carrier passes the abutment on said projection duringmovement of the second movable contact into engagement with the secondstationary contact, and the energy storedI in the free end of said armbeing eilective in returning the first movable contact into engagementwith the first stationary contact when the' force upon said actuator isreleased.

9. Apparatus of the class described comprising a stationary contact, aresilient contact carrier having a xed end and a free end and beingprovided with an abutment adjacent its free end, a contact affixed tosaid carrier adjacent its free end which is movable into and fromengagement with the stationary contact, a resilient arm having a freeend projection shorter than said contact carrier and said projectionbeing provided with an abutment, a spring having its opposite endsrockably mounted on said abutments for normally maintaining the movablecontact in engagement with the stationary contact and the free end ofsaid projection in spaced relation to said carrier, an actuator appliedto said contact carrier adjacent its flXed end on the side opposite tothat from which said projection is spaced, said arm beingperpendicularly spaced at a suillcient distance from said contactcarrier opposite to the position at which said actuator is applied topermit sufficient fiexure of the carrier in the space between the planeof said carrier and the plane of said arm to store sufficient energy insaid carrier under the influence of said actuator to move the carrierwith a snap motion when the opposing force of said spring is exceeded,and means for adjusting the free end projection of said arm to vary theforce required to actuate said contact carrier.

10. Apparatus of the class described comprising a stationary contact, aresilient contact carrier having a fixed end and a free end and beingprovided adjacent its free end with an abutment, a movable contactaflixed adjacent the free end of said carrier, a resilient arm having afree end provided with an abutment, a support, means for securing theopposite end of said arm to said support, the free ends of said carrierand arm being extended in the same direction from said support and thefree end of said arm being of less length than said carrier and beingbiased away from' said carrier, a spring rockably mounted on saidabutments and normally maintaining the movable contact in engagementwith the stationary Contact, an actuator applied to said contact carrieradjacent its fixed end, means for perpendicularly spacing said arm atsufiiclent distance from said contact carrier opposite to the positionat which said actuator is applied to permit suicient fiexure of thecarrier in the space between the plane of the carrier and the plane ofthe arm to move said carrier under the infiuence of said actuator with asnap motion to disengage the movable contact from the stationarycontact, and means for adjusting the position of the free end of saidarm to vary the force required to actuate said contact carrier.

11. Apparatus of the class described comprising first and second spacedstationary contacts, a resilient contact carrier having a fixed end anda free end and being provided adjacent its free end with an abutment,first and second movable contacts affixed to opposite sides of saidcarrier adjacent its free end, the rst being movable into and fromengagement with the first stationary contact and the second beingmovable into and from engagement with the second stationary contact, aresilient arm having a free end pro- 13 jection shorter than saidcarrier which projection is provided with an abutment, a spring rockablymounted on said abutments for normally maintaining the iirst movablecontact in engagement with the iirst stationary contact and the free endprojection of said arm in spaced relation to the.

contact carrier, an actuator applied adjacent the fixed end ofsaidcarrier upon the same face thereof which carries the rst movablecontact, said arm being perpendicularly spaced 'at-a sufficient distancefrom said contact carrier opposite to the position at which saidactuator is applied to permit sufficient ilexure of the carrier in thespace between the plane of said carrier and the plane of said arm tostore lsuiiicient energy in said carrier under the influence of saidactuator todisengage the first movable contact from the ilrst stationarycontact against the force of said spring and to rock said spring uponsaid abutments to rapidly change the directionof the force of saidspring to cause the second movable contact to engage the secondstationary contact and the abutment on said projection being spaced asufficient distance from the contact carrier and the fixed contactsbeing so disposed relative to each other and said arm that the secondmovable contact engages the second stationary contact to limit themovement of the contact carrier before it passes into lalignment withthe abutment on said projection, and means for adjusting the position ofthe free end of the flexible arm to vary the force required to actuatesaid contact carrier. i

12. Apparatus of the class described comprising first and second spacedstationary contacts, a resilient contact carrier having a fixed end anda free end provided with an abutment, rst and second movable contactsaiiixed to the opposite sides of said carrier adjacent the free endthereof, a resilient arm having a free end projection provided with anabutment, a spring rockably mounted on said abutments for maintainingthe rst movable contact in engagement with the rst stationary contactand said projection in spaced relation to said carrier, an actuatorapplied to said carrier adjacent its fixed end on the side opposite tothat from which said projection is spaced, said arm beingperpendicularly spaced at a suicient distance from said contact carrieropposite to the position at which said actuator is applied to permitsuflicient flexure of the carrier in the space between the plane of saidcarrier and the plane of said arm to store suilicient energy in saidcarrier under the iniiuence of said actuator to move the carrier with asnap motion to cause engagement of the second movable contact with thesecond stationary contact and to rock said spring upon said abutmentswhen the opposing force of saidspring is exceeded and said xed contactsbeing spaced at a suiiicient distance from each other and being sodisposed relative to the abutment on said pro- 14 free end, a resilientarm perpendicularly spaced from said contact carrier which extends insubstantially the same direction as saidl contact carrier. said armhaving a free movable end spaced 6 from said contact carrier, theterminus of which lies intermediate planes perpendicular to the oppositeends of said contact carrier, said arm having a xed end and beingprovided with an abutment adjacent its free end, and means for perlpendicularly spacing said arm from said contact carrier throughout thelength of said arm, including a spring rockably mounted upon saidabutments to space thefree end of said arm from the free end of saidcarrier, and spaced 15 arcuate-shaped connectors integral with said armand said contact carrier arranged adjacent the fixed end of said armwhich space the contact carrier at a suiilcient perpendicular distancefro'msaid arm to permit sumcient iiexure of said contact carrier in saidspace to store sufcient energy in said carrier to move its free end witha snap motion when force is applied to said contact carrier adjacentsaid connectors.

14. Apparatus of the class described comprising a stationary contact, aresilient contact carrier having a free end and being provided adjacentits free end with an abutment and with a contact which contact isarranged opposite to the stationary contact and which is movable in toand from engagement therewith, a spring for normally maintaining themovable contact in engagement with the stationary contact, said springhaving one end rockably mounted on said abutment, means extending insubstantially the same direction as said contact carrier and having afree end projection provided with an abutment on which the opposite endof said spring is rockably fmounted, and the abutment on saidprojectlonbeing perpendicularly spaced from said contact carrier and arrangedintermediate planes perpendicular to the opposite ends of said contactcarrier, an actuator applied to said carrier adjacent `its fixed end,and said means being perpendicularly spaced at sufficient 4distance fromsaid contact carrier opposite to the position at which said Y actuatoris applied to permit suilicient iiexure of said carrier in said space tostore suiiicient energy in said contact carrier to disengage the movablecontact from the stationary contact with a snap motion when force isapplied to said actuator, and the abutment on said projection being`arranged at a closer distance to the abutment on saidcarrier than tosaid actuator.

15. Apparatus of the class described comprising a stationary contact, aresilient contact carrier having a free end and 'being provided adjacentits free end with an abutmentand with a contact which contact isarranged opposite to the stationary contact and which is movable intoand from engagement therewith, an arm extending in substantially thesame direction as said contact carrier and having a fixed end and a freeend projection provided with an abutment arranged in a position which isperpendicularly spaced from said contact carrier and intermediate planesperpendicular to the opposite ends of said contact carrier, a springhaving its opposite ends rockably mounted on said abutments, an actuatorapplied t0 said c arrier adjacent its xed end on the side opposite tothat from which the arm is spaced, and said arm being perpendicularlyspaced at a suilicient distance from saidcontact carrier op-v posite tothe position at which-said actuator is applied to permit suflicientilexure of said carrier in the space between said carrier and said armto 15 store suiicient energy in saidcontact carrier to disengage themovable contact from the stationary contact when force is applied tosaid actuator, and the abutment on said arm being arranged at a closerdistance to the abutment on said carrier 5 than to said actuator.

EVERARD F. KOHL.

REFERENCES CITED The following references are of record in the 10 le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,109,953 Bates Mar. 1, 1938 15Number Number

